Exercise board



FIG. 1 is a side elevational view of an exercise board showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a left-end elevational view thereof;

FIG. 4 is a right-end elevational view thereof;

FIG. 5 is a bottom plan view thereof; and

FIG. 6 is a side perspective view thereof. 

The ornamental design for an exercise board, as shown. 